Explosion demonstration apparatus



2 SheetsSheet l INVENTOR.

ATTORNE I E BY April 8, 1958 w. G. HAYNE EXPLOSION DEMONSTRATION APPARATUS Filed June 29, 1955 April 1953 1 w. G. HAYNE 2,829,445

EXPLOSION DEMONSTRATION APPARATUS Filed June 29, 1955 2 Sheets-Sheet 2 INVEN TOR. Mum/v 6! HA m5 ATTORNEY Patented Apr. 8, 195 8 2,829,445 EXPLOSION DEMONSTRATION APPARATUS William G. Hayne, Great Neck, N. Y. Application June 29, 1955, Serial No. 518,825 2 Claims. (Cl. 3510) This invention relates to an explosion demonstration apparatus and more particularly to an apparatus for graphically exhibitng the explosive characteristics of volatile liquids.

In order to adequately and forcefully lecture on the dangers inherent in the use and storage of volatile liquids it has been found desirable to demonstrate the explosive characteristics of such liquid with the aid of a small scale explosion chamber. The lecturing and demonstrations of this nature are often carried out by groups such as the New York Board of Fire Underwriters before various diverse audiences and particularly before assemblies of school children. It is apparent then that the apparatus provided must be portable and capable of being transported from place to place. This latter requisite has been found to place certain unusual demands on the apparatus. Consider, for example, the carriage of such equipment on a cold winter day with the resulting chilling of the parts of the apparatus. This normally insignificant fact has often prevented the demonstration from being successfully performed inasmuch as the volatilization of the liquid is dependent on the temperature of its environment. Undue delays in demonstrating the principles sought to be illustrated have been alleviated by the provision of an apparatus having a heating element in accordance with the teachings of this invention.

It is the object of the present invention to provide improved demonstration apparatus of the explosion chamber type.

In carrying out the invention there is provided an explosion chamber having means at its upper end whereby the chamber can be closed or sealed by a yieldable seal and means at its lower extremity for igniting an explosive mixture. There is also include-d means for heating the explosion chamber to facilitate the volatilization of the liquid to provide the explosive mixture.

Features and advantages of the invention can be gained from the foregoing and the description of a preferred embodiment thereof which follows.

In the drawings:

Figure l is a cabinet view of the apparatus herein provided;

Figure 2 is an enlarged elevational view showing the details of construction of the explosion chamber; and

Figure 3 is a simplified wiring diagramfor the demonstration apparatus.

Referring first to Figure 1 there is shown an enclosure which serves as a housing for a high voltage transformer hereinafter described and also as a suitable mount for explosion chamber 11. The enclosure is shown with a single perforated plate 12 secured over an opening in the side thereof by several screws 13, and provided for ventilating purposes inasmuch as the transformer found within the enclosure may tend to become heated when used for a protracted period of time. Although only one ventilation opening is illustrated it is, of course, understood that any number may be provided in accordance with the ventilation requirements of the equipment utilized.

' On the upper surface of enclosure 10 is shown a manual pushbutton 14, a double throw toggle switch 15, and a pair of pilot lamps 16 and 17, preferably blue and red, respectively, and explosion chamber 11.

Reference will now be made to Figure 2 wherein is shown the details of construction of the explosion chamber. A-flanged collar 20 is provided to secure the explosion chamber 11 to enclosure 10, the collar being fastened to the enclosure by a plurality of machine screws 21 which pass through the collar flange and the top surface of the enclosure to receive nuts 22. The collar itself which surrounds the lower portion of open ended plastic cylinder 23 rigidly maintains the cylinder by means of the circumferentially disposed fastening means or screws 24. I

Spaced from the bottom of the cylinder 23 which coincides with the top surface of the enclosure 10 and internally disposed with respect to the cylinder is an inverted cup shaped member 25.

.This member has been provided as of aluminum although any suitable material may be used therefor and is held in its selected position by any convenient means such as screws 20. A threaded opening 30 provided in the discal portion of member 25 serves as the means whereby spark plug 31 is mounted in the apparatus. Directly under the surface of member 25 is a heating element 32 in the form of a resistor. Its manner of mounting is immaterial and for the sake of simplicity it is shown supported by its relatively stiff terminal wires 33 which extend through the enclosure 10 to the circuits located therein as does the two conductor leads 34 from the spark plug.

At the upper end of plastic cylinder 23 there is provided a closure device 35 which includes a lower stationary portion 36 having a depending circularly shaped section 37 which is inserted into the upper end of cylinder and secured therein by circumferentially disposed screws 40. These have been shown as wood screws inasmuch as the closure device itself is formed of wood. Integral with the depending section 37 is the rectangularly shaped section 36. A unit 42 is recessed at one edge of the section. A movable portion 43 which is congruent with respect to section 36 is pivotally connected thereto by hinge 44. A knurled thumb screw 45 is provided to pass through portion 43 and section 36 and engage nut 42 to thereby lock the two members together. A concentric opening 46 is formed passing through the entire closure 35 for a reason which will hereinafter become apparent.

In operation, the demonstration apparatus is arranged before the audience witnessing the demonstration and electric plug 47 is inserted in a convenient electric outlet. Toggle switch 15 is moved to its initial or preparatory position (upwardly in Figure 3) and immediately a circuit is completed for blue pilot lamp 16 and electric heater element 32. Illumination of the blue lamp indicates to the demonstrator that the circuit for the heater element is completed and that the apparatus is being prepared, i. e., heated, to facilitate the volatilization of the liquid to be added to the unit.

After the heater element has been energized for a period of time found adequate to heat the unit, the lecturer injects a droplet of liquid to be volatilized through the opening of closure device 35 into the interior of plastic cylinder 23. An eyedropper has been found suitable for this purpose. The thumb screw 45 is thereupon removed and movable portion 43 pivoted upwardly. A piece of tearable material, e. g., paper, is placed over section 36 to completely close the opening through the closure device 35 and portion 43 is restored to its closed position. Thumb screw 45 then passed through portion 43 and section 36 to engage nut 42 whereupon it is tightened to securely sandwich the inserted paper piece between the members of the closure device.

By thistimethe dropletof liquid which is generally gasoline has been volatilized and an explosive mixture formed within the plastic cylinder. It might be noted at this point that the dimensions of the cylinder are proportioned such that an explosive mixture results from the volatilization of a single drop of flammable liquid.

Nextthe lecturer actuates toggle switch 15 to its other operative position and immediately a circuit is completed for red pilot lamp 17. This indicates to the lecturer that the apparatus is ready for the explosion. He thereupon depresses push button 14 which completes a circuit for the primary windingSO of transformer. 51. The secondary winding 52 of thetransformer provides a voltage of 3000 volts for sparking spark plug 31. .When this occurs, the explosive mixture is ignited with the result that the paper plug closing the upper end of the plastic cylinder is blown out accompanied by a loud report.

The foregoing is explained as illustrating the explosive force of a single droplet of gasoline and the conclusion is drawn that extreme care must be exercised when handling flammable liquids and under no circumstances should the liquid or vapors resulting therefrom be brought into proximity with a flame or other heated object.

Having thus described my invention, it is to be understood that many apparently widely different embodiments of this invention can be made without departing from the spirit and scope thereof and hence the foregoing description anddrawing are to be interpreted as illustrative and not in a limiting sense.

What is claimed is:

1. An apparatus for demonstrating the explosive characteristics of volatile liquids comprising an enclosure forming an explosion chamber, the dimensions of said enclosure being proportioned so that when a drop of vol-,

atile liquid is introduced thereinto and volatizedan explosive mixture'results, said chamber being provided with a seal tearable when subjected to the force of .an explosion within said chamber for the purpose of producing I an audible report and means for permittinga torn seal activation of the igniting means for firing the explosive mixture.

References Cited in the file of this patent UNITED STATES PATENTS 1,344,722 Schulz June 29, 1920 2,201,708 Wight May 21, 1940 2,368,018 Groth ct al. Jan.23, 1945 I 2,448,203 Africano Aug. 31,1948 2,267,745 Matteson Feb. 10, 1953 

